US President Donald Trump was expected to make a decision Friday on whether to slap punitive tariffs on Mexico for allowing hundreds of thousands of migrants to cross their country to enter the United States. Crunch talks between US and Mexican officials continued through the day at the State Department in Washington, with the Trump administration demanding a tough crackdown on Central American migrants and an agreement to accept their asylum petitions inside Mexico. If a deal cannot be reached, the US intends to hit hundreds of billions of dollars' worth of imports from Mexico with five per cent tariffs beginning Monday - a move which could clobber Mexico's economy. "We're doing all right," Mr Trump said without elaborating as he returned to Washington on Friday evening from Europe, as reporters shouted questions about the negotiations with Mexico. But after leaving Ireland earlier in the day he tweeted that "there is a good chance" that an agreement can be reached. However, Mr Trump added, "If we are unable to make the deal, Mexico will begin paying Tariffs at the per cent level on Monday!" Mexican Foreign Minister Marcelo Ebrard met with US officials at the State Department for a third straight day to discuss US demands for a crackdown on migrants. Talks went on late into the afternoon, and there was no news on whether they were making progress. Mexican President Andres Manuel Lopez Obrador said Friday morning he was "optimistic" for a deal. White House official Marc Short said they were poised to issue the legal notification Friday for the tariffs to go ahead on Monday. However, said Mr Short, Vice President Mike Pence's chief of staff, "I think there is the ability, if negotiations continue to go well, that the president can turn that off at some point over the weekend." The Trump administration has demanded Mexico take tough action to halt the flow of hundreds of thousands of migrants fleeing chronic poverty and violence in Guatemala, Honduras and El Salvador, who are hoping to request asylum in the United States. In recent months the migrant groups have been dominated by families with children. The number of migrants detained or blocked at the border surged to 144,000 in May, triple the level a year earlier. The US insists Mexico must lock down its border with Guatemala to the south and agree to let asylum seekers register their claims inside Mexico, presumably to wait there while their applications are processed. Last week Mr Trump announced that, starting from June 10, a five per cent tariff would be applied to all goods from export-dependent Mexico, rising by five percentage points each month to a high of 25 per cent, until US demands on migrant controls were satisfied. The move takes direct aim at Mexico's economy, which is heavily dependent on trade with the United States. The United States imports about $350 billion each year in goods from Mexico, including $128 billion in automobiles, auto parts and engines, and $26 billion in agricultural products and processed foods. Mexico has scrambled to appease Washington, agreeing Thursday to deploy 6,000 National Guard troops to its southern border, blocking a new migrant caravan and freezing the bank accounts of suspected human traffickers. "We're going to have a national guard nationwide, so it should help accompany the return of migrants to their home countries," Lopez Obrador said Friday. Businesses on both sides of the border were deeply worried about the impact of the tariffs. The economies have become deeply dependent upon each other, though Mexico stands to be hit much harder than the United States. The US Chamber of Commerce issued a statement from 140 US business and agricultural associations opposing unilateral tariffs. "Tariffs on Mexican imports would harm US consumers, workers, farmers and businesses of all sizes across all sectors, making us less competitive and undermining efforts to negotiate strong trade deals in the future," they said.